problem has changed
Thanks for your response.
I went through all the uninstall/reinstall/delete .dat file instructions once more. Then I entered a new menu test on this page: cssmenuwriter.php
When I return to this page in order to edit the menu, I click on the little script icon, but instead of seeing a CSS Menu Writer edit button, I am only seeing an "edit CSS" button, that would allow me to edit the properties of the <div> tag. In other words, the icon I'm clicking is for the <div> tag and not for the menu.